1. Field of the Invention
This invention generally relates to trocar systems including obturators and, more specifically, to blunt tip obturators having hollow shafts for insertion of optical instruments.
2. Discussion of the Prior Art
Trocar systems have been of particular advantage in facilitating less invasive surgery across a body wall and within a body cavity. This is particularly true in abdominal surgery where trocars have provided a working channel across the abdominal wall to facilitate the use of instruments within the abdominal cavity.
The trocar systems of the past typically included a cannula, which provides the working channel, and an obturator which is used to place the cannula across the abdominal wall. The obturator is inserted into the working channel of the cannula and then pushed through the abdominal wall with a penetration force of sufficient magnitude resulting in penetration of the abdominal wall. Once the cannula is in place, the obturator can be removed.
Obturators have been developed with an attempt to reduce the penetration force of the abdominal wall. For example, sharp blades, sharp edges and piercing points have typically been used to enable the obturator to cut or pierce its way through the abdominal wall. While the sharp blades, sharp edges and piercing points have facilitated a reduced penetration force, they have also caused larger trocar site defects. These trocar site defects may have to be sutured closed resulting in increased operating room costs and procedural time. Moreover, once the abdominal wall has been penetrated, the sharp blades, sharp edges and piercing points of the obturator may still cause damage to the vessels and organs that lie within the peritoneal cavity. For example, the blades on the obturators that serve to cut tissue during insertion may also cut vessels or puncture organs that may result in patient injury or surgical complications.
In some cases, shields have been provided with the obturators in order to sense penetration of the abdominal wall and immediately shield the sharp blades, edges or piercing points. These shielding systems are typically complex and require some time to deploy and, as such, many have not been effective in protecting the vessels and organs against the sharp blades, edges or piercing points. Accordingly, there remains a need in the art for an improved bladeless obturator that separates tissue during insertion through a body wall. Moreover, there is a need for a transparent blunt tip obturator having a hollow shaft to enable insertion of an optical instrument to view the insertion of the obturator through the body wall.